# name : Returns the position and length of a substring that matches a pattern. pattern, regex
# key : prxsubstr.
# key : regex.prxsubstr.
# contributor: Shuguang Sun
# --
call prxsubstr(${1:'/foo/'}, ${2:source}, ${3:position}${4:$$(yas-choose-value '(", lenght" ""))}$0);